Tube structure



' Aug. 28, 1945. A. L. PARKER 2,383,733

- I TUBE STRUCTURE Fi1ed March-31, 1941 Patented Aug. 28, 1945 TUBE STRUCIURE Arthur L. Parker, Cleveland, Ohio, assignor to The Parker Appliance Company, flleveland, Ghio, a

corporation of Ohio Application March 31, 1941, Serial No. 386,211 2 Claims. (01. 138-55) The invention relates generally to flexible tubing and couplings therefor, and it primarily seeks to provide a, nove1 form of flexible tubing which is sufilciently light in weight and also strong enough for use in aircraft fuel and hydraulic systems.

At present the tubing used on hydraulic lines is usually composed of an inner liner of rubber or synthetic rubber material, an intermediate tube braided fabric, and a covering of thin rubberized fabric. The braided fabric is usually of cotton and if the tubing is to be used for high pressures, there are usually several layers of the fabric braid and there may or may not be a separate layer of rubber between each layer. Even when only one layer of fabric braid is used,

there is often a second layer of rubber betweenthe braid and-the outside fabric. This results in tubing of considerably thick wall section which objectionably reduces the flexibility and increases the weight thereof. The outer fabric covering is usually either in the form of a spirally wound tape or in the form of a sheet wrapped around the tubing; In the form of spirally wound tape, the overlapping edges form a spiral ridge of appreciable size. If a sheet is wrapped around the tubing, the tubing is not perfectly ends.

In its more detailed nature, the invention has for an object to provide a tubing structure comprising an inner tube of rubber or a suitable rubber substitute such as neoprene," a surrounding sleeve formed of braided glass fibers, and an exterior coating of a flexible Plastic which penetrates the braided glass fiber sleeve through to the inner tube and serves as a coating for the 'to or having an aflinityfor the material of the inner tube so that the tubing can be vulcanized together, thereby forming a permanent bond between the inner tube and its surrounding sleeve oLcoated, braided glass fibers.

With the above and; other objects inview which will more fully appear, the nature of the invention will be more clearly understood by round and there is a seam where the wrapping following the description, the appended claims, and the several views illustrated in the accompanying drawing.

In the drawing-- Figure 1 is a part side elevation and part central longitudinal section of a tube structure embodying the invention.

Figure 2 is a vertical cross section of the tubing structure illustrated in Figure 1.

Figure 3 is a part central longitudinalt section and side elevation of a coupling adaptable for efiiciently coupling the tubing structure illustrated in Figures 1 and 2.

Figure 4 is a view similar to Figure 3 illustrating a coupling adapted for efiiciently coupling the tubing structure illustrated in Figure 5.

Figure 5 is a vertical cross section illustrating the modified form of tubing structure.

In the tubing structure illustrated in Figures 1 and 2 of the drawing, there is included a rubber or synthetic rubber inner tube 5 which is loosely inserted within an enclosing sleeve 6 of braided glass fibers. 0ver the sleeve 6 there is applied a coating of a suitable flexible plastic i, said coating being applied in a manner for causing the'plastic to penetrate the interstices of the sleeve 6 and coat the glass fibers with a thin film oi the plastic. This coating reaches the inner side of the braided glass fiber sleeve,

as at 8, so that said sleeve is in fact completely embedded within the thin coating of the plastic. The protective coating 1, 8 preferably comprises either a vinyl polymer or a chlorinated vinyl polymer, although. other suitably flexible plastics or lacquers may be employed.

in a relatively sharp end extremity insertible between the inner tube 5 and the surrounding sleeve structure 6, I, 8 in the manner illustrated in Figure 3. When the female elementor nut I I ofthe coupling is threaded home on the male element,

a flared clamp'ring I 2 mounted therein and en-- the external surface of the tapered male element theglass braided fibers serves to cushion the clamping pressure so that the metal seats do not shear the glass fibers. The Joint is sealed against In Figure 5 of the drawing, there is. illustrateda modified form of the tubing which is particularly adaptable to use in low pressure lines, or lines which may at times be subjected to suction intemaliy. In such lines it is preferable to bond the rubber 5 to the surrounding braided glass fiber sleeve. In this form of the invention, it is preferred that the coating material which coats the braided sleeve and forms a protective film around the individual glass fibers comprising the same shall also act as a bond to secure the inner tube and the surrounding sleeve together as at M. When the braided glass fiber sleeve and the inner rubber tube are to be bonded in this manner, it is preferred to use but one material as the bonding agent and the protective oughly penetrate and form a thin film on the individual multiple fibers in the braided strands,'

thus when the fibers flex in the tubing while it v is in service, the fibers are cushioned against direct rubbing contact one with the other, and severing or breaking of the fibers is prevented.

In Figure 4 of the drawing, there is illustrated a coupling adapted for securely clamping tube structures in which the inner tube and the surrounding, braided glass fiber sleeve are bonded.

It would, ofcourse, be possible, even in a tube extension 9. The flexible plastic I, l surrounding thus bonded; to separate the tube and sleeve and clamp the tube extremity in the manner illustrated in Figure ,3, but since this is a somewhat diificult and time consumingoperation, it

may be found desirable to provide a coupling of the nature illustrate-din Eigure 4. "This coupling maybe somewhat similar to the coupling of Figure 3 but in it the whole end of the tube is clamped between the tapered male element extento the extension [6 and is forced into the tube sicn i6 and a split and internally ridged ferrule H which surrounds the tube and in opposition end clamping position illustrated in Figure 4 by the inclined surface l8 and the end abutment 88 of the female element when this element is threaded home on the male element. During this clamping 01' the tube end, the extremity oi the tube is crowded, as at 20, to additionally 1. A flexible tubular structure comprising an inner tube of rubber, a surrounding sleeve of braided glass fibers, and an external coating of a flexible plastic penetrating through the interstices ofsaid sleeve and individually coating the fibers thereof and cushioning them against inutual severing contact, said penetrating coating being bonded to said inner tube.

2. A flexible tubular structure comprising an inner tube of rubber, a surrounding sleeve 01' braided glass fibers, and an external coating of a flexible plastic penetrating through the interstices of said sleeve and individually coating the fibers ,thereof and cushioning them against mutual severing contact, said plastic corresponding with or having an afilnity for said rubber tube and said plastic and said rubber tube being v'ul canizedtogether.

ARTHUR L. PARKER. 

